In an advertisement, a pizza shop claims its mean delivery time is 30 minutes. a consumer group believes that the mean delivery time is greater than the pizza shop claims. a random sample of 41 delivery times has a mean of 31.5 minutes with standard deviation of 3.5 minutes. does this indicate at a 5% significance level that the mean delivery time is longer than what the pizza shop claims?

We conclude that at a 5% significance level that the mean delivery time is longer than what the pizza shop claims.

Step-by-step explanation:

We are given the following in the question:

Population mean, μ = 30 minutes

Sample mean, = 31.5 minutes

Sample size, n = 41

Alpha, α = 0.05

Sample standard deviation, s = 3.5 minutes

First, we design the null and the alternate hypothesis

We use one-tailed z test to perform this hypothesis.

Formula:

Putting all the values, we have

Now,

Since,  

We reject the null hypothesis and accept the alternate hypothesis.

Thus, we conclude that at a 5% significance level that the mean delivery time is longer than what the pizza shop claims.

answer: i can’t tell you that

step-by-step explanation: